Atm traffic management device

Abstract

A traffic management unit for implementing Traffic Management (TM) of Available Bit Rate (ABR) traffic on an Asynchronous Transfer Mode (ATM) network is described. The traffic management unit comprises a traffic management processor coupled to a traffic management memory. The traffic management processor is coupled between a data processor and an ATM interface. An Ethernet workstation is coupled to the data processor through an Ethernet interface. An ATM switch is coupled to the traffic management processor through the ATM interface. The traffic management unit is implemented as a unit separate from the cell scheduling data processor. In addition, in order to utilize network congestion information more efficiently, VCs are grouped according to their output destinations or their path through the network. Congestion feedback for one VC is applied to other VCs within the group. The traffic management startup procedure is streamlined by using a preliminary profile and modifying this preliminary profile in accordance with feedback congestion data received. TM can be disabled for destination end stations not implementing TM. To further streamline the traffic management processes, memory based rate lookup tables containing pre-calculated profile sets are utilized. Each VC uses one of these tables thus obviating the need for time and hardware intensive multiplications and additions. In addition, the traffic management unit implements multicast domain shaping by mapping destination data multicast addresses and protocol types, found in input frames or packets, into destination VCs, thus eliminating the wasteful listen and discard processes associated with broadcast characteristic of Ethernet.